Most of the world’s packaging materials are petroleum-based plastics which are not biodegradable. The current global consumption of non-biodegradable plastics is more than 200 million tons, with an annual growth of approximately 5%, which represents one of the largest focus areas for crude oil. Furthermore, this situation demonstrates the increasing need to use alternative bio-based raw materials. Until now, petrochemical-based plastics such as polyethylene, polypropylene, polyethylene terephthalate, polyvinylchloride, polystyrene, and polyamide have been increasingly used as packaging materials because of their wide availability at relatively low cost and their good mechanical performance. Nowadays, their use has to be restricted because they are not biodegradable, and therefore they pose serious ecological problems. Plastic packaging materials are also often contaminated by foodstuffs and biological substances, making recycling of these materials impracticable and often uneconomical. This has quicked much research in recent years into the development of products such as bio-based polymers as could replace these non-biodegradable materials in the packaging industry. Many bio-based polymers such as cellulose, starch, alginate, and chitosan have been studied by many researchers. The interest in using natural fibers such as different plant fibers has increased dramatically during last few years. With regard to the environmental aspect it would be very interesting if natural fibers like jute, banana, and coir could be used instead of artificial fibers as reinforcement in some structural applications. Investigations carried out in this field have shown that stiffness, hardness and dimensional stability of plastics have also been improved by incorporation of lignocellulosic fillers. Natural fibers have many advantages compared to synthetic fibers; for example they have low cost, low density, low abrasion, competitive specific mechanical properties, reduced energy consumption, they are biodegradable. In addition, they are renewable raw materials and have relatively high strength and stiffness and cause no skin irritation.
2.1. Seaweed Based Seaweed based polymer has been broadly utilized as a part of bio packaging, food and biomedical applications in terms of their known biocompatibility, bio absorbability, biodegradability and nontoxicity. These polymers can be degradable without enzymatically. Commonly three seaweed-derived hydrocolloids polysaccharides are available in nature that has diversified application as bio polymeric film such as alginate, carrageenan and agar. However, there are others seaweed hydrocolloids polysaccharides, which are less significant like mannitol, fucoidan and funoran.Gracilaria and Gelidium can create gelatin like substances primarily known as agar. Red Algae Kappaphycus and Betaphycus are the important sources of carrageenan. The film forming and binding ability makes it suitable for the use of packaging material.
2.1.1. Alginate Alginates, a naturally occurring polysaccharide, were obtained from marine brown algae (Sargassum). Algae are one kind of seaweed. Algae, like any other plant, require three magical ingredients: (i) light, (ii) water, and (iii) nutrients. Alginates are linear copolymers of b-(1-4)-linked D-mannuronic acid and a- (1-4)-linked L-glucuronic acid units, which exist widely in many species of brown seaweeds.
Alginate has been used in a wide range of industries such as food, textile printing, paper and pharmaceuticals, and for many other novel end-uses. As a water-soluble polymer, alginate is an excellent gel-forming material capable of holding a large amount of water. Alginate has been utilized to develop biodegradable or edible films due to its unique colloidal properties such as thickening, stabilizing, suspending, film-forming, gel producing, and emulsion stabilizing properties.
Alginate is the most widely used material for bio polymeric film. It is a natural polysaccharide derived from marine plants. Alginate is of interest as a potential biopolymer film component because of its unique colloidal properties, which include thickening, stabilizing, suspending, film forming, gel producing, and emulsion stabilizing. The main objective of this work was to develop renewable and biodegradable alginate-based Nano composite films by incorporating NCC for food-packaging applications.
2.1.2. Carrageenan Carrageenan extracted from red algae specifically from the Rhodophyceae family. It’s consisting of linear sulfated polysaccharides of D-galactose and 3,6- anhydro-D-galactose (3,6-AG). This is a specific type of seaweed is common in the Atlantic Ocean near Europe, North America and Britain. It is a complex mixture of five distinct polymers designated ι-, κ-, λ-, µ-, and ν - carrageenan. Among those, three major types lambda (λ), kappa(κ) and iota(ι). There sulfate contents are 41%, 33% and 20%. Classification of carrageenan was made based on its solubility in KCl. λ -, ι - and κcarrageenan membranes reveal better mechanical properties. In order to meet the new renewable resources for the production of edible and biodegradable material, carrageenan can be used as an interesting alternative to produce comestible films and coatings, food and beverage, bio packaging. This opaque or colored packaging is widely used in food containers, trays, cups, wraps and other packaging designed to preserve light or UV sensitive products. But pure carrageenan films limit its use for food packaging.
2.1.3. Agar Agar (AG), a gelatinous polysaccharide that is extracted from marine red algae such as Gelidiumand Gracilaria spp, is one of the most promising polysaccharide for developing biodegradable packaging films. It has been widely used for the preparation of bio basedfilms due to its high mechanical strength and moderate water-resistant properties. Moreover, AG based films were found to be heat-sealable. Upon considering the best characteristics of AG separately, we speculated that their combination would lead to better films than those formed by each individual material alone.